This invention relates to nuclear reactors and more particularly to nuclear reactors designed to operate at very high temperatures for the purpose of supplying process heat.
Whereas most nuclear reactors heretofore built for power were designed to ultimately transform water into steam to drive a steam turbogenerator, with the rising cost of energy from fossil fuels, it now appears that there will be a commercial market for providing heat from nuclear reactors for industrial applications other than the generation of electricity. The term "process heat" is generally used to describe the category of reactors that are being designed for the purpose of supplying thermal energy to be used in chemical or physical applications other than the generation of electricity.
Certain considerations which were foremost when dealing with steam cycles for the generation of electricity, via the use of steam turbines, give way to other more important criteria when process heat applications are concerned. In high-temperature gas-cooled nuclear power reactors, the reactor core may be maintained at a temperature sufficient to produce a heat-extraction stream having a temperature of as high as 750.degree. C.; however, for process heat applications, usable thermal energy at a temperature of 800.degree. C. to 950.degree. C. may be desired. When reactors operate at such very high temperatures, changes in reactor design are often dictated by such higher temperature considerations, and particularly from the standpoint of safety, there is much room for improvements in reactor design.